1. Technical Field
The invention relates to a device comprising a cam shaft phase setter and a vacuum pump for mounting on an internal combustion engine, and also to an internal combustion engine with the device mounted.
2. Description of the Related Art
In order to reduce brake pedal forces in motor vehicles, in particular passenger cars and light-duty commercial vehicles, the vehicles are equipped with pneumatic brake servos. In conventional passenger car spark-ignition engines, the partial vacuums required for brake servos are applied by the suction pipe partial vacuums acting behind the suction inlet system throttle valve. In diesel engines and also modern spark-ignition engines with fuel injection, the suction pipe partial vacuums which arise during operation are in many cases not sufficient for powering the brake servos, because the load control deviates from conventional spark-ignition engines. Such internal combustion engines therefore use a separate vacuum pump which is driven by the respective engine. These pumps are generally driven by a cam shaft of the engine and are usually flange-mounted to a facing side of the cylinder head.
In order to increase the output and torque, and to reduce the emissions and fuel consumption, modern passenger car engines are increasingly equipped with cam shaft phase setters which are charged with engine oil pressure and using which the phase angle of an inlet cam shaft or outlet cam shaft or both cam shafts can be adjusted relative to an engine crankshaft. Usually, separate functional units of cam shaft phase setters and vacuum pumps are arranged on the cam shaft. Due to the required seal and coupling between the functional units and the respective drive, and as applicable between each other, and also in view of the configuration of the oil feed and oil eduction, such arrangements incur a comparatively elaborate construction. A direct coupling between the vacuum pump and a cam shaft also restricts the torque level and the arrangement of the vacuum pump.
DE 102 60 546 A1 discloses arranging a vacuum pump and a cam shaft phase setter coaxially next to each other on the same rotational axis. A rotor of the phase setter is placed, secured against rotating, on the cam shaft to be adjusted. The stator is driven by the crankshaft. The rotor is connected, secured against rotating, to the vacuum pump via a coupling. The vacuum pump comprises a housing which is flange-mounted to a cylinder head of the internal combustion engine, and a drive shaft which protrudes through the cylinder head and is connected, secured against rotating, to the rotor of the phase setter by means of the coupling. The vacuum pump is supplied with lubricating oil through a central bore of its drive shaft through the cylinder head.